JOURNAL OF MICROSCOPICAL SCIENCE. 
DESCRIPTION OF PLATE X, 
Illustrating Mr. E. Ray Lankester’s paper on the Structure 
and Origin of the Spermatophors, or Sperm-ropes of two 
Species of Tubifex. 
Fig. 
1.—Sperm-rope of Tubifex rivulorum. 
¥.—Surface of the same, with the filaments in a state of vibration. 
3.—The same a little more deeply focussed. 
4,—Optical longitudinal section of the same. 
a. Axial canal. 4. Dark line lying in inner bright layer. c. Striated 
or fibrous layer. a. Outer bright layer. e. Free ends of the 
spermatozoa, 7.¢., vibrating filaments. 
5.—The same more deeply focussed. 
6.—Spermatozoa of Tubifexr rivulorum. 
7.—Transverse section of sperm-rope of 7. rivulorum, proximal end ; letters 
as in fig. 4. 
8.—Short spermatophor of 7. rivulorum. 
9.—Headless ditto. 
10.—Diagram to show the form of the head. 
11.—Portion of a sperm-rope of Z. rivulorum torn and teazed, showing 
spiral structure. 
12.—A portion of a cement-form, 7.¢., a spermatophor devoid of sperma- 
tozoa. 
13.—Incompletely cemented spermatophor. 
14.—Sperm-rope of Tubifex umbellifer. 
15.—A specimen of the same, in movement. 
16.—Form of seta in the first ten dorsal pairs of fascicles of 7. umbellifer 
(camera sketch). 
17.—Form of the posterior dorsal and central sete: (camera sketch). 
18.—Diagram of orifice of the copulatory pouch of Tubifexr rivulorum ; 
showing the reduplication or ridge causing the conical head of the 
spermatophor. 
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